Mixed adenoneuroendocrine carcinoma of the stomach – a case report

Abstract

Neuroendocrine tumours represent a heterogeneous group of neoplasia arising from different anatomical locations, with approximately 50% of gastrointestinal origin. Main parameters in the evaluation of each case include tumour morphology, mitotic cell count, and Ki-67 index. Mixed adeno-neuroendocrine carcinomas (MANECs) are rare aggressive neoplasms consisting of both adenocarcinomatous and neuroendocrine cells, each component constituting at least 30% of the lesion. Our case represents 77-year-old polymorbid patient who, due to signs of acute bleeding in the upper gastrointestinal tract with anaemic syndrome, underwent a gastroscopic examination for melena with the finding of an ulcer lesion on the front wall of the stomach at the junction of the body and the antrum. The control gastroscopic examinations with biopsies, at first only signs of chronic gastritis with Helicobacter pylori positivity were histologically proven, then fragments of high-grade tubular to tubulovillous adenoma and structures of moderately differentiated tubular adenocarcinoma were found. Histological analysis of the gastric resection showed mixed adeno-neuroendocrine carcinoma with lymphangioinvasion.